The purpose of this project is to examine how proxies who consent to psychiatric treatment or research on behalf of an elderly family member make their decisions. As the lifespan increases, the elderly can be more prone to the development of serious illnesses, some of which (e.g., Alzheimer's disease) affect cognitive functions and consequently may impair the ability to make competent treatment decisions (i.e., give a competent informed consent). Stanley & colleagues demonstrated that elderly individuals, particularly those with Alzheimer's disease, had difficulty comprehending consent information. In addition, when compared with other patient groups, patients with senile dementia, even in the early stages, had trouble determining what was a "reasonable" treatment or research project. Therefore, someone else will have to make these decisions for those elderly people who are incapable of doing so themselves. As the elderly segment of the population expands, the need for substitute decision-makers or proxies will also expand. Currently, in standard treatment setting, "informal proxies" (i.e., next of kin of elderly patients) are commonly used even though the elderly person is not legally incompetent. In research, federal regulations require "a legally authorized representative" (i.e. some form of proxy) consent on behalf of the ill patient in order to include that person in a study. Again, the closest next of kin is often called upon to serve as the proxy. Despite the widespread use of proxies in treatment and research settings, there is very limited knowledge of the ability and willingness of potential proxies to perform this task. Several models for proxy decision-making have been proposed in the medical and legal literature but little is known about the practicality and applicability of these models to actual treatment and research settings. This project is the first large scale empirical study designed to examine proxy consent in psychiatric treatment and research. The research, a continuation of an NIMH funded project, is of practical importance to practitioners, researchers and policy makers in that it will help to determine whether proxy consent, as currently conceptualized, is a workable model of substitute decision-making. A workable model of proxy consent must be developed in order to make treatment decisions for incompetent elderly and conduct research on psychiatric conditions which result in a loss of functional competency. Two studies are proposed in this project; one in which proxy decision- making for elderly people is examined using hypothetical treatment and research projects, and a second in which elderly patients about to undergo actual psychiatric treatment or research and their family members are evaluated to determine when proxies are used and how they reach decisions.